Color and design tools
Use the color tools to move between a design value and something you can use in a page. HEX to RGB turns #ff0000 into rgb(255, 0, 0), while HSL exposes hue, saturation and lightness for adjustments. Palette tools help create related swatches; gradient, shadow and border-radius generators give you a preview and CSS for a specific effect. The controls run locally, so you can experiment without creating an account.
Contrast checks are useful when choosing text and background colors. Enter the actual foreground and background pair, including the background a translucent color will sit on. A contrast ratio measures that pair; it does not establish that an entire interface is accessible. Text size, focus indicators, non-color cues and interactive states still need review in the finished design.
Color conversions have limits as well. A browser preview depends on the screen and its color handling, and a simple CMYK conversion is not a print proof with a printer profile. Keep the original color values when handing a design to a print workflow. For web work, test the generated styles in their real context: a palette that looks clear on a swatch board can behave differently with small text, photographs or dark-mode surfaces.